BEIJING, June 5 (Reuters) - China will expand its wheat stockpile by increasing buying from domestic producers as the world's top producer and consumer of the staple grain looks to secure supply amid recent weather-related damage to global production.

Frost has hit crops in No.1 exporter Russia and both dryness and excessive rains have threatened yields in the European Union, igniting worries about lower global supplies in the second half of 2024, a key production and marketing period.

Wheat buyers in Asia, Africa and the Middle East, which account for two-thirds of global imports of the staple, have been caught out with relatively little supply after the weather disruptions that unexpectedly sent prices surging from April.

China's state-owned agricultural stockpiler Sinograin said in a notice on Wednesday it and its affiliated units will increase purchases of wheat produced in 2024 from major regions for its reserves. It said it had already started buying in some regions.

This comes as Chinese buyers in recent months cancelled wheat shipments from U.S and Australia after price fluctuations.

Sinograin in January had also said it would raise its purchases of domestic corn.

The world's biggest grain importer this year sharply expanded its budget to stockpile grains and edible oils by 8.1% and implemented its first food security law aimed at achieving "absolute self-sufficiency" in staple grains. (Reporting by Siyi Liu, Mei Mei Chu, Albee Zhang and Bernard Orr in Beijing; Editing by Muralikumar Anantharaman and Jan Harvey)